References which might be material to the present disclosure include U.S. Pat. No. 4,635,026 which discloses a PTC device in a relatively complex enclosure or housing which completely surrounds the apparatus according to FIG. 4 of the drawings. Various stages of fabrication of the PTC apparatus in conjunction with appropriate electrode system is set forth.
U.S. Pat. No. 3,467,937 discloses a thermistor disk which is held within a rimmed elastic housing of silicon rubber having an outer lip which is flexible. The housing wraps around the disk on the opposite major surfaces, and includes an edge located flange or lip for use in an interference fit in a socket.
U.S. Pat. No. 4,327,282 is directed to a heating strip which is made of a PTC material, one or more units thereof, assembled in a sandwich which is disclosed in FIG. 2 wherein the sandwich is clamped in a U-shaped border or rail along the edges thereof.
U.S. Pat. No. 4,426,573 shows another heating element which is defined by a sandwich of layers enclosing a disk made of PTC material, all enclosed with a tight hermetic skin.
Another reference is a brochure published by Raychem Corporation which describes a polySwitch circuit component which is a PTC disk. Mention is made thereat of use in toys and other devices which are battery powered with the polySwitch devices incorporated.